refactor: synthesize previous refactors

This reverts commit 4b721f7543.

src/main.rs

@@ -277,165 +277,29 @@ fn run_tui(
 
 // ── Drawing ──────────────────────────────────────────────────────────────────
 
-fn draw(f: &mut Frame, app: &App) {
-    let size = f.area();
-
-    let main_chunks = Layout::default()
-        .direction(Direction::Vertical)
-        .constraints([
-            Constraint::Length(1), // title bar
-            Constraint::Min(0),    // content
-            Constraint::Length(1), // tile bar
-            Constraint::Length(1), // status / command bar
-        ])
-        .split(size);
-
-    draw_title(f, main_chunks[0], app);
-    draw_content(f, main_chunks[1], app);
-    draw_tile_bar(f, main_chunks[2], app);
-    draw_bottom_bar(f, main_chunks[3], app);
-
-    // Overlays (rendered last so they appear on top)
-    if matches!(app.mode, AppMode::Help) {
-        f.render_widget(HelpWidget, size);
-    }
-    if matches!(app.mode, AppMode::ImportWizard) {
-        if let Some(wizard) = &app.wizard {
-            f.render_widget(ImportWizardWidget::new(wizard), size);
-        }
-    }
-    if matches!(app.mode, AppMode::ExportPrompt { .. }) {
-        draw_export_prompt(f, app);
-    }
-    if app.is_empty_model() && matches!(app.mode, AppMode::Normal | AppMode::CommandMode { .. }) {
-        draw_welcome(f, main_chunks[1]);
-    }
+fn fill_line(left: String, right: &str, width: u16) -> String {
+    let pad = " ".repeat((width as usize).saturating_sub(left.len() + right.len()));
+    format!("{left}{pad}{right}")
 }
 
-fn draw_title(f: &mut Frame, area: Rect, app: &App) {
-    let dirty = if app.dirty { " [+]" } else { "" };
-    let file = app.file_path.as_ref().and_then(|p| p.file_name()).and_then(|n| n.to_str()).map(|n| format!(" ({n})")).unwrap_or_default();
-    let title = format!("  improvise  ·  {}{}{} ", app.model.name, file, dirty);
-    let right = " ?:help  :q quit ";
-    let pad = " ".repeat((area.width as usize).saturating_sub(title.len() + right.len()));
-    let line = format!("{title}{pad}{right}");
-    f.render_widget(Paragraph::new(line).style(Style::default().fg(Color::Black).bg(Color::Blue).add_modifier(Modifier::BOLD)), area);
-}
-
-fn draw_content(f: &mut Frame, area: Rect, app: &App) {
-    if app.formula_panel_open || app.category_panel_open || app.view_panel_open {
-        let side_w = 32u16;
-        let chunks = Layout::default().direction(Direction::Horizontal).constraints([Constraint::Min(40), Constraint::Length(side_w)]).split(area);
-        f.render_widget(GridWidget::new(&app.model, &app.mode, &app.search_query), chunks[0]);
-
-        let side = chunks[1];
-        let open_panels = [app.formula_panel_open, app.category_panel_open, app.view_panel_open];
-        let panel_count = open_panels.iter().filter(|&&b| b).count() as u16;
-        let ph = side.height / panel_count.max(1);
-        let mut y = side.y;
-
-        if app.formula_panel_open {
-            f.render_widget(FormulaPanel::new(&app.model, &app.mode, app.formula_cursor), Rect::new(side.x, y, side.width, ph));
-            y += ph;
-        }
-        if app.category_panel_open {
-            f.render_widget(CategoryPanel::new(&app.model, &app.mode, app.cat_panel_cursor), Rect::new(side.x, y, side.width, ph));
-            y += ph;
-        }
-        if app.view_panel_open {
-            f.render_widget(ViewPanel::new(&app.model, &app.mode, app.view_panel_cursor), Rect::new(side.x, y, side.width, ph));
-        }
-    } else {
-        f.render_widget(GridWidget::new(&app.model, &app.mode, &app.search_query), area);
-    }
-}
-
-fn draw_tile_bar(f: &mut Frame, area: Rect, app: &App) {
-    f.render_widget(TileBar::new(&app.model, &app.mode), area);
-}
-
-fn draw_bottom_bar(f: &mut Frame, area: Rect, app: &App) {
-    match app.mode {
-        AppMode::CommandMode { ref buffer } => draw_command_bar(f, area, buffer),
-        _ => draw_status(f, area, app),
-    }
-}
-
-fn draw_status(f: &mut Frame, area: Rect, app: &App) {
-    let mode_badge = mode_name(&app.mode);
-    let search_part = if app.search_mode { format!("  /{}▌", app.search_query) } else { String::new() };
-    let msg = if !app.status_msg.is_empty() { app.status_msg.as_str() } else { app.hint_text() };
-    let yank_indicator = if app.yanked.is_some() { " [yank]" } else { "" };
-    let view_badge = format!("  {}{}  ", app.model.active_view, yank_indicator);
-    let left = format!("  {mode_badge}{search_part}  {msg}");
-    let right = view_badge;
-    let pad = " ".repeat((area.width as usize).saturating_sub(left.len() + right.len()));
-    let line = format!("{left}{pad}{right}");
-    let badge_style = mode_style(&app.mode);
-    f.render_widget(Paragraph::new(line).style(badge_style), area);
-}
-
-fn draw_command_bar(f: &mut Frame, area: Rect, buffer: &str) {
-    f.render_widget(Paragraph::new(format!(":{buffer}▌")).style(Style::default().fg(Color::White).bg(Color::Black)), area);
-}
-
-fn draw_export_prompt(f: &mut Frame, app: &App) {
-    let area = f.area();
-    let popup_w = 64u16.min(area.width);
-    let x = area.x + area.width.saturating_sub(popup_w) / 2;
-    let y = area.y + area.height / 2;
-    let popup_area = Rect::new(x, y, popup_w, 3);
-
-    f.render_widget(Clear, popup_area);
-    let block = Block::default().borders(Borders::ALL).border_style(Style::default().fg(Color::Yellow)).title(" Export CSV — path (Esc cancel) ");
-    let inner = block.inner(popup_area);
-    f.render_widget(block, popup_area);
-    let buf = if let AppMode::ExportPrompt { buffer } = &app.mode { buffer } else { "" };
-    f.render_widget(Paragraph::new(format!("{buf}▌")).style(Style::default().fg(Color::Green)), inner);
-}
-
-fn draw_welcome(f: &mut Frame, area: Rect) {
-    let w = 58u16.min(area.width.saturating_sub(4));
-    let h = 20u16.min(area.height.saturating_sub(2));
+fn centered_popup(area: Rect, width: u16, height: u16) -> Rect {
+    let w = width.min(area.width);
+    let h = height.min(area.height);
     let x = area.x + area.width.saturating_sub(w) / 2;
     let y = area.y + area.height.saturating_sub(h) / 2;
-    let popup = Rect::new(x, y, w, h);
-
-    f.render_widget(Clear, popup);
-
-    let block = Block::default().borders(Borders::ALL).border_style(Style::default().fg(Color::Blue)).title("  Welcome to improvise  ");
-    let inner = block.inner(popup);
-    f.render_widget(block, popup);
-
-    let lines: &[(&str, Style)] = &[
-        ("Multi-dimensional data modeling — in your terminal.", Style::default().fg(Color::White)),
-        ("", Style::default()),
-        ("Getting started", Style::default().fg(Color::Blue).add_modifier(Modifier::BOLD)),
-        ("", Style::default()),
-        (":import <file.json>    Import a JSON file", Style::default().fg(Color::Cyan)),
-        (":add-cat <name>        Add a category (dimension)", Style::default().fg(Color::Cyan)),
-        (":add-item <cat> <name> Add an item to a category", Style::default().fg(Color::Cyan)),
-        (":formula <cat> <expr>  Add a formula, e.g.:", Style::default().fg(Color::Cyan)),
-        ("  Profit = Revenue - Cost", Style::default().fg(Color::Green)),
-        (":w <file.improv>       Save your model", Style::default().fg(Color::Cyan)),
-        ("", Style::default()),
-        ("Navigation", Style::default().fg(Color::Blue).add_modifier(Modifier::BOLD)),
-        ("", Style::default()),
-        ("F C V                  Open panels (Formulas/Categories/Views)", Style::default()),
-        ("T                      Tile-select: pivot rows ↔ cols ↔ page", Style::default()),
-        ("i  Enter               Edit a cell", Style::default()),
-        ("[ ]                    Cycle the page-axis filter", Style::default()),
-        ("?  or  :help           Full key reference", Style::default()),
-        (":q                     Quit", Style::default()),
-    ];
-
-    for (i, (text, style)) in lines.iter().enumerate() {
-        if i >= inner.height as usize { break; }
-        f.render_widget(Paragraph::new(*text).style(*style), Rect::new(inner.x + 1, inner.y + i as u16, inner.width.saturating_sub(2), 1));
-    }
+    Rect::new(x, y, w, h)
 }
 
-// ── Helpers ──────────────────────────────────────────────────────────────────
+fn draw_popup_frame(f: &mut Frame, popup: Rect, title: &str, border_color: Color) -> Rect {
+    f.render_widget(Clear, popup);
+    let block = Block::default()
+        .borders(Borders::ALL)
+        .border_style(Style::default().fg(border_color))
+        .title(title);
+    let inner = block.inner(popup);
+    f.render_widget(block, popup);
+    inner
+}
 
 fn mode_name(mode: &AppMode) -> &'static str {
     match mode {
@@ -465,4 +329,258 @@ fn mode_style(mode: &AppMode) -> Style {
     }
 }
 
+fn draw(f: &mut Frame, app: &App) {
+    let size = f.area();
 
+    let main_chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([
+            Constraint::Length(1), // title bar
+            Constraint::Min(0),    // content
+            Constraint::Length(1), // tile bar
+            Constraint::Length(1), // status / command bar
+        ])
+        .split(size);
+
+    draw_title(f, main_chunks[0], app);
+    draw_content(f, main_chunks[1], app);
+    draw_tile_bar(f, main_chunks[2], app);
+    draw_bottom_bar(f, main_chunks[3], app);
+
+    // Overlays (rendered last so they appear on top)
+    if matches!(app.mode, AppMode::Help) {
+        f.render_widget(HelpWidget, size);
+    }
+    if matches!(app.mode, AppMode::ImportWizard) {
+        if let Some(wizard) = &app.wizard {
+            f.render_widget(ImportWizardWidget::new(wizard), size);
+        }
+    }
+    if matches!(app.mode, AppMode::ExportPrompt { .. }) {
+        draw_export_prompt(f, size, app);
+    }
+    if app.is_empty_model() && matches!(app.mode, AppMode::Normal | AppMode::CommandMode { .. }) {
+        draw_welcome(f, main_chunks[1]);
+    }
+}
+
+fn draw_title(f: &mut Frame, area: Rect, app: &App) {
+    let dirty = if app.dirty { " [+]" } else { "" };
+    let file = app
+        .file_path
+        .as_ref()
+        .and_then(|p| p.file_name())
+        .and_then(|n| n.to_str())
+        .map(|n| format!(" ({n})"))
+        .unwrap_or_default();
+    let title = format!("  improvise  ·  {}{}{} ", app.model.name, file, dirty);
+    let right = " ?:help  :q quit ";
+    let line = fill_line(title, right, area.width);
+    f.render_widget(
+        Paragraph::new(line).style(
+            Style::default()
+                .fg(Color::Black)
+                .bg(Color::Blue)
+                .add_modifier(Modifier::BOLD),
+        ),
+        area,
+    );
+}
+
+fn draw_content(f: &mut Frame, area: Rect, app: &App) {
+    let side_open = app.formula_panel_open || app.category_panel_open || app.view_panel_open;
+
+    let grid_area;
+    if side_open {
+        let side_w = 32u16;
+        let chunks = Layout::default()
+            .direction(Direction::Horizontal)
+            .constraints([Constraint::Min(40), Constraint::Length(side_w)])
+            .split(area);
+
+        grid_area = chunks[0];
+
+        let side = chunks[1];
+        let panel_count = [
+            app.formula_panel_open,
+            app.category_panel_open,
+            app.view_panel_open,
+        ]
+        .iter()
+        .filter(|&&b| b)
+        .count() as u16;
+        let ph = side.height / panel_count.max(1);
+        let mut y = side.y;
+
+        if app.formula_panel_open {
+            let a = Rect::new(side.x, y, side.width, ph);
+            f.render_widget(
+                FormulaPanel::new(&app.model, &app.mode, app.formula_cursor),
+                a,
+            );
+            y += ph;
+        }
+        if app.category_panel_open {
+            let a = Rect::new(side.x, y, side.width, ph);
+            f.render_widget(
+                CategoryPanel::new(&app.model, &app.mode, app.cat_panel_cursor),
+                a,
+            );
+            y += ph;
+        }
+        if app.view_panel_open {
+            let a = Rect::new(side.x, y, side.width, ph);
+            f.render_widget(
+                ViewPanel::new(&app.model, &app.mode, app.view_panel_cursor),
+                a,
+            );
+        }
+    } else {
+        grid_area = area;
+    }
+
+    f.render_widget(
+        GridWidget::new(&app.model, &app.mode, &app.search_query),
+        grid_area,
+    );
+}
+
+fn draw_tile_bar(f: &mut Frame, area: Rect, app: &App) {
+    f.render_widget(TileBar::new(&app.model, &app.mode), area);
+}
+
+fn draw_bottom_bar(f: &mut Frame, area: Rect, app: &App) {
+    match app.mode {
+        AppMode::CommandMode { ref buffer } => draw_command_bar(f, area, buffer),
+        _ => draw_status(f, area, app),
+    }
+}
+
+fn draw_status(f: &mut Frame, area: Rect, app: &App) {
+    let search_part = if app.search_mode {
+        format!("  /{}▌", app.search_query)
+    } else {
+        String::new()
+    };
+
+    let msg = if !app.status_msg.is_empty() {
+        app.status_msg.as_str()
+    } else {
+        app.hint_text()
+    };
+
+    let yank_indicator = if app.yanked.is_some() { " [yank]" } else { "" };
+    let view_badge = format!("  {}{}  ", app.model.active_view, yank_indicator);
+
+    let left = format!("  {}{search_part}  {msg}", mode_name(&app.mode));
+    let line = fill_line(left, &view_badge, area.width);
+
+    f.render_widget(Paragraph::new(line).style(mode_style(&app.mode)), area);
+}
+
+fn draw_command_bar(f: &mut Frame, area: Rect, buffer: &str) {
+    f.render_widget(
+        Paragraph::new(format!(":{buffer}▌"))
+            .style(Style::default().fg(Color::White).bg(Color::Black)),
+        area,
+    );
+}
+
+fn draw_export_prompt(f: &mut Frame, area: Rect, app: &App) {
+    let buf = if let AppMode::ExportPrompt { buffer } = &app.mode {
+        buffer.as_str()
+    } else {
+        ""
+    };
+    let popup = centered_popup(area, 64, 3);
+    let inner = draw_popup_frame(f, popup, " Export CSV — path (Esc cancel) ", Color::Yellow);
+    f.render_widget(
+        Paragraph::new(format!("{buf}▌")).style(Style::default().fg(Color::Green)),
+        inner,
+    );
+}
+
+fn draw_welcome(f: &mut Frame, area: Rect) {
+    let popup = centered_popup(area, 58, 20);
+    let inner = draw_popup_frame(f, popup, "  Welcome to improvise  ", Color::Blue);
+
+    let lines: &[(&str, Style)] = &[
+        (
+            "Multi-dimensional data modeling — in your terminal.",
+            Style::default().fg(Color::White),
+        ),
+        ("", Style::default()),
+        (
+            "Getting started",
+            Style::default()
+                .fg(Color::Blue)
+                .add_modifier(Modifier::BOLD),
+        ),
+        ("", Style::default()),
+        (
+            ":import <file.json>    Import a JSON file",
+            Style::default().fg(Color::Cyan),
+        ),
+        (
+            ":add-cat <name>        Add a category (dimension)",
+            Style::default().fg(Color::Cyan),
+        ),
+        (
+            ":add-item <cat> <name> Add an item to a category",
+            Style::default().fg(Color::Cyan),
+        ),
+        (
+            ":formula <cat> <expr>  Add a formula, e.g.:",
+            Style::default().fg(Color::Cyan),
+        ),
+        (
+            "  Profit = Revenue - Cost",
+            Style::default().fg(Color::Green),
+        ),
+        (
+            ":w <file.improv>       Save your model",
+            Style::default().fg(Color::Cyan),
+        ),
+        ("", Style::default()),
+        (
+            "Navigation",
+            Style::default()
+                .fg(Color::Blue)
+                .add_modifier(Modifier::BOLD),
+        ),
+        ("", Style::default()),
+        (
+            "F C V                  Open panels (Formulas/Categories/Views)",
+            Style::default(),
+        ),
+        (
+            "T                      Tile-select: pivot rows ↔ cols ↔ page",
+            Style::default(),
+        ),
+        ("i  Enter               Edit a cell", Style::default()),
+        (
+            "[ ]                    Cycle the page-axis filter",
+            Style::default(),
+        ),
+        (
+            "?  or  :help           Full key reference",
+            Style::default(),
+        ),
+        (":q                     Quit", Style::default()),
+    ];
+
+    for (i, (text, style)) in lines.iter().enumerate() {
+        if i >= inner.height as usize {
+            break;
+        }
+        f.render_widget(
+            Paragraph::new(*text).style(*style),
+            Rect::new(
+                inner.x + 1,
+                inner.y + i as u16,
+                inner.width.saturating_sub(2),
+                1,
+            ),
+        );
+    }
+}